When a computer is first turned on or is otherwise reset, a central processing unit implements a reset function to validate and initialize components in the system. When there is more than one CPU or multiple processor cores, each performs a similar reset function. The reset function typically is stored in non-volatile memory as a Basic Input-Output System (BIOS). As an example, the CPU reads instructions from a location in non-volatile memory corresponding to a reset vector. Usually, during a first phase of the reset function, the local cache is validated based on executable instructions are read from the non-volatile memory. The CPU then executes instructions that are stored in the local cache to validate and perform diagnostics for other components of the CPU, including one or more processor cores and associated caches. After the processor cores and caches have been validated, the reset sequence can continue to complete the initialization sequence.